Mathematics for IGCSE & O level - Proportion (Section 2 - No. 1)
When *y* is inversely proportional to the square root of *x*, and *y* = 4 when *x* = 16. What will be the value of x when y = 2?
4
16
32
64
설명
Since y = k / sqrt(x), then 4=k/sqrt(16); then k=16. Then y = 16/sqrt(x); and 2=16/sqrt(x), then sqrt(x)=8 and x=64